Photo-induced dissociation of protonated tryptophan TrpH+: A direct dissociation channel in the excited states controls the hydrogen atom loss

2004 ◽  
Vol 6 (10) ◽  
pp. 2628-2632 ◽  
Author(s):  
H. Kang ◽  
C. Dedonder-Lardeux ◽  
C. Jouvet ◽  
S. Martrenchard ◽  
G. Grégoire ◽  
...  
Keyword(s):  
Hydrogen Atom ◽  
Excited States ◽  
Dissociation Channel ◽  
Atom Loss ◽  
Direct Dissociation

Recent advances in Minisci-type reactions and applications in organic synthesis

2020 ◽  
Vol 24 ◽  
Author(s):  
Wengui Wang ◽  
Shoufeng Wang
Keyword(s):  
Free Radical ◽  
Hydrogen Atom ◽  
Organic Synthesis ◽  
Radical Reactivity ◽  
Atom Loss ◽  
Radical Generation ◽  
In Situ Generation ◽  
Thermal Cleavage ◽  
Synthetic Chemist

Abstract:: Minisci-type reactions have become widely known as reactions that involve the addition of carbon-centered radicals to basic heteroarenes followed by formal hydrogen atom loss. While the originally developed protocols for radical generation remain in active use today, in recent years by a new array of radical generation strategies allow use of a wider variety of radical precursors that often operate under milder and more benign conditions. New transformations based on free radical reactivity are now available to a synthetic chemist looking to utilize a Minisci-type reaction. Radical-generation methods based on photoredox catalysis and electrochemistry, which utilize thermal cleavage or the in situ generation of reactive radical precursors, have become popular approaches. Our review will cover the remarkably literature that has appeared on this topic in recent 5 years, from 2015-01 to 2020-01, in an attempt to provide guidance to the synthetic chemist, on both the challenges that have been overcome and applications in organic synthesis.

scholarly journals Highly excited states of a hydrogen atom in a strong magnetic field

1983 ◽  
Vol 28 (1) ◽  
pp. 7-21 ◽  
Author(s):  
J. B. Delos ◽  
S. K. Knudson ◽  
D. W. Noid
Keyword(s):  
Magnetic Field ◽  
Hydrogen Atom ◽  
Strong Magnetic Field ◽  
Excited States

Discrimination between hydrogen atom and proton abstraction in the quenching of n, π* singlet-excited states by protic solvents

1998 ◽  
Vol 102 (3) ◽  
pp. 486-492 ◽  
Author(s):  
Werner M. Nau ◽  
Gerhard Greiner ◽  
Hermann Rau ◽  
Massimo Olivucci ◽  
Michael A. Robb
Keyword(s):  
Hydrogen Atom ◽  
Excited States ◽  
Proton Abstraction ◽  
Protic Solvents

Hydrogen atoms in the presence of a homogeneous magnetic field: a variational approach

1978 ◽  
Vol 56 (12) ◽  
pp. 1545-1548 ◽  
Author(s):  
H. S. Brandi ◽  
Belita Koiller
Keyword(s):  
Magnetic Field ◽  
Hydrogen Atom ◽  
Excited States ◽  
Three Dimensional ◽  
Homogeneous Magnetic Field ◽  
Basis Functions ◽  
Variational Parameter ◽  
Hydrogen Atoms ◽  
Wide Range ◽  
Free Hydrogen

We propose a variational scheme to obtain the spectrum of the hydrogen atom in the presence of an external homogeneous magnetic field. We use two different sets of basis functions to diagonalize the Hamiltonian describing the system, namely, the eigenfunctions of the free hydrogen atom and of the three-dimensional harmonic oscillator, both having their radial coordinates properly scaled by a variational parameter. Because of its characteristics, the present approach is suited to describe the ground state as well as an infinite number of excited states for a wide range of magnetic field strengths.

Isomerization of dideuteroethylene photosensitized by Cd(3P1)

1968 ◽  
Vol 46 (6) ◽  
pp. 995-998 ◽  
Author(s):  
Shigeru Tsunashima ◽  
Shun-Ichi Hirokami ◽  
Shin Sato
Keyword(s):  
Hydrogen Atom ◽  
Excited States ◽  
Principal Mode ◽  
Temperature Range ◽  
Primary Products ◽  
Trans Isomerization

An investigation of the Cd(3P1)-photosensitized isomerization of dideuteroethylene has been made over the temperature range 275–350 °C. Principal primary products in the reaction of trans-1,2-dideu-teroethylene are cis-1,2- and asym-1,1-dideuteroethylenes. Minor products are ethane, acetylene, and n-butane, in amounts which are about three orders of magnitude smaller than those of the isomers.Decomposition of ethylene into hydrogen and acetylene, which is the principal mode of reaction in the case of Hg(3P1), was scarcely observed for the Cd(3P1)-photosensitized reaction.The two-excited-states mechanism previously proposed (1, 2) has been applied to explain hydrogen atom scrambling and cis–trans isomerization. It has been found necessary to modify the above mechanism to explain the results.

XXXVII.—The Van der Waals Force between a Proton and a Hydrogen Atom. II. Excited States

1948 ◽  
Vol 62 (3) ◽  
pp. 360-368 ◽  
Author(s):  
C. A. Coulson ◽  
C. M. Gillam
Keyword(s):  
Hydrogen Atom ◽  
Closed Form ◽  
Interaction Energy ◽  
Excited States ◽  
Internuclear Distance ◽  
Van Der Waals ◽  
Quantum States ◽  
Van Der Waals Force ◽  
Image Position

SummaryThe interaction energy, or Van der Waals force, between a proton and a hydrogen atom in any one of its allowed quantum states is calculated in terms of the internuclear distance R by an expansion of the formAll the coefficients up to and including E5 are obtained in closed form. For values of R for which the expansion is valid, the coefficients are determined absolutely, no approximations being introduced.

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